ML19351A459

From kanterella
Jump to navigation Jump to search
LER 89-010-00:on 891109,determined That All Three Svc Water Pump Discharge Strainers Unqualified for Appropriate Seismic Criteria.Caused by Design Deficiency for Original Installation.New Pipe Support installed.W/891208 Ltr
ML19351A459
Person / Time
Site: Millstone Dominion icon.png
Issue date: 12/08/1989
From: Komosky G, Scace S
NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-010-02, LER-89-10-2, MP-13837, NUDOCS 8912180045
Download: ML19351A459 (4)
v • d • e


Text

% ,

l N; (

'- DNAM nm

- o'a rc' o"'c:* 8:'a a 8'r**' *:ran c:aa*=c"'

w$sI.7ua'Ea'e@$ttNwYeomp

  • 1 -

P.O. Box 270 g -

M 'as7[En N v D A any HARTFORD. CONNECTICUT 06414-0270 Northeast Nucear Enrgy Company (203)666-5000 December 8, 1989 MP-13837 Re: 10CFR50.73(a)(2)(ii)-

U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Reference:

Facility Operating License No. DPR-65 i Docket No. 50-336 Licensee Event Report 89-010-00 Gentlemen:  ;

4 This letter forwards Licensee Event Report 89-010-00 pursuant to paragraph 50.73(a)(2)(ii), reporting any event or condition that resulted in the nuclear power plant _;

being in a condition that was outside the design basis of the plant.

I Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

)k$

/Stephv)n E. Scace cate. -

Station Superintendent Millstone Nuclear Power Station

SES/GEK:tp -

Attachment:

LER 89-010-00 cc: W. T. Russell, Recion I Administrator W. J. Raymond, S'enior Resident inspector, Millstone Unit Nos.1, 2 and 3 G. S. Vissing, NRC Project Manager, Millstone Unit No. 2 1 l

l l

45 991208 NN h

S CK0500ffg6

f NHC Form 3% U 8, NVCLE AR RE GULATO8Y COMMISSION APPHQVLD OMb NO. 3tt$-0 44 (6-89)

EXPIRE S: 4 /30!c?

4_

Estimat.d mformat6on buroen per rt.sponsa Coll.ction to comply r ou.st: LO with this 0 hrs Forward LICENSEE EVENT REPORT (LER)  %@d*0'a'nQ.nTf*Bf,'$76'!0[t[Mfu'e,.ar t

Ft.Oulatory Commission W.shmoton. DC 20666. an In. Paper Managem.vork c' nt ano DucoR.auctio.n 1 Wa Nngton DC Proi.ct 20603 (3160-Ot041. O F ACILn Y NAME (11 .

DUskt I NUMeth d) *"

  • Millstone Nuclear Power Station Unit 2 ol 6101 ol of 3 i316 1lOFl 0l 3 TITLt (4)

Inoperable Service Water Strainers EVENT DAlt tbs LERPANPEA afo nEpont DATF f71 OTHE A F ACtITf S INVOL VED (81 MONT V DAY YEAR NEAR MONTH DAY YEAR F ACILIT Y NAMEb 0l 6l 010l Ol l l 1 1 0l4 8 9 8 l9 0l1l0 0l 0 1l2 0l8 8l 9 ol sl ol 010l l l  ;

QPERATING THIS REPORT l$ f1EING SJBM)TTED PURSUANT TO THE REQUIREMENTS OF to CFR 0 (Ch.Ck one or more of th toHowmgH11l 20 40210) ; 20 402ter 60. 731al(2) tiv t 73 71(t')

20 4064aMum 60. 36 lc H1) 60.73(aH2Hv) 73 fite) .

',W 0l0l0 POWgR - - ~

20 406<autHui 20 406 taut Hun 60.36 eH2) 60 73laH2)D)

60. 73. < a H2iivii)
60. 73 (a H2)(viliH Ay

[ (TgR, tgi'g, T.xt NRC Form 366A) 20 406(aH t)(iv) \' 60 73;aH2Hil) 60 73taH2HvuoqB) 20 405f aH1)hvi 60 73(aH2HiiO 60 73f aH2Hx)

LICENSEE CONT ACT FOR TH1$ LE84 (12i NAME TELEPHONE NUMBE A Gary E. Komosky, Engineer, Ext 4725 E cwt 2l0l3 4l4l7l-l1l7l9l1 COMDLETE ONE UNE FOR E ACH COMPONENT F AILURE DESCRIBED IN THIS REPOAT #13:

CAUSE SYSTEM COMPONENT $UNEk* d CAUSE SYSTEM COMPONENT h$kgk 7d B Bl S l SlTlR Al 0 l 6 l0 Y l l l l l l l l II I I I I I II I I I I SUPPLEMENTAL REPOAT EXPECTED nel MONTH DAY YEAR E XPE C{ED "

T vEs tit ves. comoi.e. EXPECTED SveM!SS!ON DATE) ] NO H 0l1 3l1 9l1 Assi u :T oma to i400 spac... t. . apprommat iy t>et , smoi.-so c. iyp.wntien wesi pe)

On November 9,1989 at approximately 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br /> with the reactor plant in Mode 5 (09 power, 91'F, 0 psig), it was analyticall> determined that all three Service Water pump discharge strainers were not qualified

, to the appropnate seismic criteria. As a result of this condiuon, both Service Water headers, hence both

! Emergency Diesel Generators and both Shutdown Coohng loops, were declared inoperable. An Unusual l Event was declared at 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br />. All operations involvmg core alterations or positive reactivity changes I

were suspended as required by the plant's Technical Specifications. A total oi seven Limiting Conditions for Operation were entered. A Request For Enforcement Discretion was requested and received in order to take exception to the Technical Specification requirement to establish Containment Integrity in accordance with Action Statement 3.6.2.2. A new pipe support was designed and mstalled at the outlet flange of each of the three Service Water Stramers. All Limiting Conditions for Operation were met and the Unusual Esent was terminated on November 14,1989 at 0310 hours0.00359 days <br />0.0861 hours <br />5.125661e-4 weeks <br />1.17955e-4 months <br />.

l l

l l

orm 366 Rj

NRC Form 36bA , U 6. tWOLE AR REGULQTORY COMMISSION APPROVED OMB NO 3160-0104 (6-89) E XPIRE 6: 4t30 92 Estimated buroen per response to comply with tNs LtCENSEE EVENT REPORT (LER) '"j5,"'l,"f cy,cyany*g*j,$,"',*g ,,*fn*,*c'd,,

TEXT CONTINUATION ana R.oorts vanagement er nch (p-630L U S. Nuctear Repuistory Commission. W ashington DC P0666. anc te.

the Pape< work Reauction Protect (3160-01Cwh Office of Management anc Dvoget. Washencion DC 20603 F ACILfTY NAME (1) DOCKET NUMBER (2i (Fn NLMpFm sto PAOL m YEAR N N-Millstone Nuclear Power Station U"il 2 0l 6l 0l 0j 0l3 l3 l6 bl9 0l 1l0 0l0 0l 2 OF 0[3 TEXT (1f more space is roowered use acortionat NRC form 366A s) Oh 1, Deeriotion of Event On November 9,1989 at approximately 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br /> with the reactor plant in Mode 5 (09 power, 91'F, 0 psig), it was analytically determined that all three Service Water pump discharge strainers-were not qualified to the appropriate seismic criteria. As a result of this condition, both Service Water headers, and hence both Emergency Diesel Generators and both Shutdown Coolmg loops, were declared inoperable. An Unusual Esent was declared at 1645 hours0.019 days <br />0.457 hours <br />0.00272 weeks <br />6.259225e-4 months <br />.

While conducting an internal audit of design calculauons, an irregularity was identified with the original vendor design calculations for the strainer anchorage. Upon further review, it was speculated that a miscommunication took place between the Architect / Engineer and the trainer vendor that resulted in a strainer anchorage design that was inadequate, in addition, the hitti bolts used to supplement the imbedded anchors for the strainers were not reviewed under the 1 & E Bulletin 79-02 re-analysis effort at Milb. tone Unit 2. A re-analysis of the anchor bohs was then performed and it indicated that they did not meet the operabihty acceptance criteria for 79-02, i.e., their safety factor was less than two. Based on this information, it was decided that the ,

anchorage was inadequate and new supports were required.

Operations personnel complied with the required Technical Specifications; all operations involving core alterations or positive reactivity changes were suspended. Action Statements entered were 3.1.2.1, 3.1.2.3, 3.4.1.3, 3.7.tt Ib, 3.6.1.2, 3.S.2.2, and 3.9.15.

There were no automatic system responses as a result of this event,

11. Cause of Evem The root cause of this event is a design deficiency for the original installation. A contributing factor was the failure to include the strainer hilti bohs in the support anchorage review per l&E Bulletin 79-02.

For the design deficiency, it appears that the Architect / Engineer was not aware that the strainer vendor had modeled the section of the Service Water system that meluded his strainers in order to develop the loading on the strainer. When the system configuration was changed dunny construction the strainer vendor was not informed and consequently the structural analysis of the stramer was not reviewed to evaluate the resuhant impact on the strainers due to these changes.

For the failure associated with the strainer hihi bolts in accordance with I & E Bulletin 79-02 program, the assumption was made that component anchorage utilized embedded anchors as this was the normal practice. In the case of the strainer anchorage, hilti bohs were utilized in combination wnh embedded anchors.

NRC Form 366A (6-89)

NRC Foem 3%c u 6, NucLEC4 QEQUWWoRY COMMISSION APFHoVED oMD NO Jt60-Ot04

.s. (640) EXPIRES cr30/92

  • Estimated buroen per response to comply with this 60 LlCENSEE EVENT REPORT (LER) ,

TEXT CONTINUATION '"'*;"Of,@j',','di,'*'s.n,en,f,

.no neports u.n.nement er "','g u,[f't,*c'f,,,

<p-s3on s Nucien, Regulatory Comnussion. Washington. DC 20666. and to the 8'aperwork Reduction Protect (3160-01041 office of Manage *ent and Buopet. Washington. De 20603

- F ACILrrY NAML o) DOCKET NUMBER (2) i.tn NUMcF A mi FAGEtai YEAR hiilktone Nuclear Power Station Unh 2 ~ -

ol 6l ol oj ol3 l3 l6 8l9 0l1l0 0l0 0l 3 OF 0l3 Text at more space is reaunea, uso acition , NRc Form 3%A si on 111. Annivsk of Frent This event is teportable in accordance with 10CFR50.73 (a)(2)(ii)(B), reporting any event or condition that resuhed in the nuclear power plant being in a condition that was outside the design basi > of the plant.

As a result of this condition, both Service Water headers, hence both Emergency Diesel Generators and both Shutdown Coohng loops, were declared inoperable. All operations involving core alterations or positive reactivity changes were suspended as required by the plant's Technical Specifications. This condition resulted in entermp a total of seven Technical Specification Limiting Conditions for Operation. A Request For Enforcement Discretion was requested and approved in order to take exception to the Technical Specification requirement to establish Containment integrity in accordance with Action Statement 3.6.2.2. Application for this request was made so that the containment equipment hatch could be positioned over the containment opening without .

latching it in place. Positioning the hatch in this manner permitted the services passing through the equipment hatch to remain intact thereby allowing the shut-down work to continue. Credit has been taken for this hatch positioning scenario for containment closure controls following a loss of Shutdown Cooling in response to Generic Letter 88-17. It was feh that the seismic disqualification of the Service Water system condition was no more limiting than the loss of Shutdown Cooling condition. The installation of the new supports was accomplished with the Service Water system physically operating.

There were no Safety Consequences as a result of this esent since the plant experienced no seismic events. By engineering judgement, the original supports would have performed their intended function even though the anchor belt safety factor did not meet the enteria of I&E Bulletin 79-02.

The Unusual Event was declared on November 9,1989 at 1845 hours0.0214 days <br />0.513 hours <br />0.00305 weeks <br />7.020225e-4 months <br /> and was terminated on Nosember 14,1989 at 0310 hours0.00359 days <br />0.0861 hours <br />5.125661e-4 weeks <br />1.17955e-4 months <br /> or a total time of four days, nine hours, and twenty-five mlnutes.

IV. Corrective Action A new pipe support was designed, fabricated, and installed at the outlet flange of each of the three Service Water Strainers which provides the required support for all Design Basis Events.

To ensure that other components withm the plant are not anchored with either hilti bolts or a combination of embedded anchors and hilti bolts, a review will be performed to verify the existing anchorage. This review will be performed on safety related components only. It is expected that the review will be completed by January 31, 1991. It should be noted that it is felt that the strainer anchorage problem was an isolated case as the use of hilti bolts in this manner is not common engineering practice; the common practice is to anchor components of this type with embedded anchors.

V. Additional Information RP Adams Co. Ntodel No. VDWS-80 strainer Similar LER's: None Ells Code Identifierc l

Strainer: BS-STR-A060 l

l NRC Form 366A (6-89)

I

Retrieved from "https://kanterella.com/w/index.php?title=ML19351A459&oldid=2344647"